Exam 3, arrhythmias and heart block blonder Flashcards
What is an AV block
delay or interruption in transmission of an impulse from the atria to the ventricles due to anatmoic or functional impairment in conduction system
What are major causes of AV blocks
increased vagal tone fibrosis and sclerosis of conduction system IHD Cardiomyopathy and myocarditis Congenital Heart disease Familial AV block
majority of AV blocks are due to what
fibrosis and sclerosis of conduction system
second most common cause of AV blocks is what
Ischemica heart disease
What drugs can induce AV blocks
digitalis CCB (non DHP) beta blockers amiodarone adenosine
What surgeries can casue AV blocks
cardiac surgery catheter ablation of arrhythmias transcatheter VSD closure alcohol septal ablation for HOCM TAVr(transcatheter AV replacement)
What characterizing a first degree AV block on EKG
PR interval >.20 milliseconds
1 large box
What are the types of second degree AV block are there
Mobitz I, Wenckebach
Mobitz II,
What is a 3rd degree AV block
no atrial impulses reach ventricle in 3rd degree AVB
what is difference with HR in AV block and dissociation
block HR is slow
dissociation is VTach
What is the most common cardiac arrhythmia
Afib
What is bpm of AFib
300-600 bpm
how does AFib change CO
decreases filling from increased rate encroaching on diastolic filling time
What are the main risk factors for Afib
HTN heart disease
CHD
RF in underdeveloped countries
What is paroxysmal afib
AF that terminates spontaneously or with intervention within 7 days of onset
may recur with variable frequency
What is persistent Afib
fails to self terminate within 7 days
pharmacologic or electrical cardioversion usually required to restore Normal Sinus Rhythm (NSR)
What is Long Standing persistent Afib
AFib that has lasted for more than 12 months
What is permanent Afib
persistent Afib where a joint decision has been made by the patient and clinicion to no longer pursue a rhythm control strategy
What group is considered low risk of AFib
“lone” Afib
15-30%
younger males
frequently familial, low risk of thrombo-embolus
What is recurrent Afib
90% afib patients have asymptomatic recurrent episodes lasting up to 48 hours
What is subclinical Afib
Afib detected in asymptomatic patients without a prior Dx. Many of these pateints have paroxysmal Afib
What are symptoms of Afib
palpitations, syncope, dyspnea, fatigue
What are preciptating causes of Afib
exercise, emotion, alcohol, holiday heart syndrome
What would you find on PE of Afib
mitral valve disease, especially MS, CHF findings
